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  • The Formation of Astrophysical Dust

    Creator:
    Mauney, Christopher M.
    Abstract:
    The formation of carbonaceous and silicate precursor molecules to astrophysical dust grains is investigated. Using density functional theory (DFT) in combination with global optimization techniques, the ground-state binding energies of dust precursors are determined. These results are employed in atomistic nucleation theory (ANT) to predict the critical size and nucleation...
    Resource Type:
    Dissertation
    Full Text:
    of Astrophysical Dust Abstract approved: Davide Lazzati The formation of carbonaceous and silicate

  • Off-Axis Gamma Ray Burst Contribution to the Diffuse Gamma Ray Background in the 100-600 keV Range

    Creator:
    Hodges, Isaac
    Abstract:
    Gamma ray bursts (GRBs) are short, intense pulses of gamma rays that emit radiation in a narrow beam. Unless the beam is oriented towards the observer, it is often difficult to resolve the bursts against the diffuse gamma ray background (DGRB). The DGRB is a measured source of gamma rays...
    Resource Type:
    Honors College Thesis
    Full Text:
    . Tueller. Cosmic X-Ray Back- ground and Earth Albedo Spectra with Swift BAT. The Astrophysical Journal, 689

  • Zero kinetic energy photoelectron spectroscopy of polycyclic aromatic hydrocarbons

    Creator:
    Zhang, Jie
    Abstract:
    In this dissertation, I present electronic spectra of a few polycyclic aromatic hydrocarbons (PAHs): tetracene, pentacene, pyrene, benzo[g,h,i]perylene and benzo[a]pyrene using resonantly enhanced multiphoton ionization (REMPI) and zero kinetic energy (ZEKE) photoelectron spectroscopy. The work of tetracene and pentacene also combine a laser desorption source with a ZEKE spectrometer, demonstrating...
    Resource Type:
    Dissertation
    Full Text:
    study is to offer a database for astrophysical modeling, in terms of both direct line identification

  • Zero Kinetic Energy Photoelectron Spectroscopy of Polycyclic Aromatic Hydrocarbons

    Creator:
    Harthcock, Colin
    Abstract:
    In this dissertation, I describe spectroscopic studies of jet-cooled polycyclic aromatic hydrocarbons (PAH) and one nitrogen substituted PAH (PANH) using pulsed field zero kinetic energy (ZEKE) photoelectron spectroscopy and resonantly enhanced multiphoton ionization (REMPI) spectroscopy. Recently, there has been a demand for far-infrared (FIR) spectral information of astrophysically relevant molecules...
    Resource Type:
    Dissertation
    Full Text:
    astrophysical environment, we have initiated a systematic study of polycyclic aromatic hydrocarbons

  • Journey to the Center of GW170817: Bayesian parameter estimation of outflows from binary neutron star mergers

    Creator:
    Rodriguez, Isabel J.
    Abstract:
    The discovery of GW170817 provided the first empirical evidence that merging binary neutron star systems are both progenitors of short gamma-ray bursts, as well as the primary sites of the nucleosynthetic rapid-neutron capture process. Initially detected as gravitational wave (GW) and gamma-ray burst (GRB) triggers, GW170817 was well-localized and follow-up...
    Resource Type:
    Masters Thesis
    Full Text:
    . By using Bayesian parameter estimation analysis to connect astrophysical data with numerical models

  • The lag–luminosity correlation in time-resolved episodes of long gamma-ray bursts

    Creator:
    Kowash, Samuel J.
    Abstract:
    We present an analysis of the relationship between spectral lag and luminosity in time-resolved segments of long gamma-ray bursts detected by BATSE, an experiment aboard the Compton Gamma Ray Observatory satellite. For full bursts, there is a well-established correlation between the lag, which is easily computed, and the total burst...
    Resource Type:
    Honors College Thesis
    Full Text:
    Astrophysical Journal, 486(2):928, Sept. 1997. ISSN 0004-637X. doi: 10.1086/304566. URL http

  • Monte Carlo Radiation Transfer Simulations of Gamma Ray Burst Prompt Emission

    Creator:
    Parsotan, Tyler M.
    Abstract:
    Gamma Ray Bursts (GRBs) are the most energetic explosions in the Universe, producing up to $\sim10^{53}$ ergs of energy in the first few seconds of their emission -- the so-called prompt phase that is dominated by high energy X-ray and $\gamma$-ray photons. The very large luminosities released in these events...
    Resource Type:
    Dissertation
    Full Text:
    make measurements of nearly every astrophysical system, each theoretical model that attempts to

  • Deriving relationships between number of observed short gamma ray bursts and viewing angle

    Creator:
    Micallef, John T.
    Abstract:
    Gamma ray bursts are some of the brightest events in the entire observable universe. Since the late 1960’s, thousands of gamma ray bursts have been observed and they have been researched extensively. However, there are still many mysteries which remain unsolved. One such mystery is whether or not the viewing...
    Resource Type:
    Undergraduate Thesis
    Full Text:
    Statistics,” ​The Astrophysical Journal​, vol. 548, no. 2, pp. 522–531, 2001.  [4] ​S. Carroll, “The

  • Search for Non-Einsteinian Polarization Modes in the Gravitational-Wave Background using NANOGrav’s 12.5 Year Data Set

    Creator:
    Laal, Nima
    Abstract:
    I led a collaborative project involving a search for an evidence of a gravitational wave background (GWB) with all the spatial correlations allowed by general metric theories of gravity using NANOGrav’s 12.5 year data set. The search found no substantial evidence in favor of the existence of such correlations. The...
    Resource Type:
    Masters Thesis
    Full Text:
    International Pulsar Timing Array. This work was published in the Astrophysical Journal Letters on December

  • Searches for a General Transverse Polarization Mode of Gravity using Pulsar Timing Arrays

    Creator:
    Laal, Nima
    Abstract:
    Given the recent advancements in the field of pulsar timing pertaining to the detection of a stochastic gravitational wave background (GWB), it is now the perfect time to perform tests of gravity via exploration of the correlation signature between the timing data of pairs of pulsars induced by the polarization...
    Resource Type:
    Dissertation
    Full Text:
    arrays by studying the polarization content of an elusive astrophysical phenomenon named the